The Mystic Falls Codex

A graduate student in psychology who ends up as the human faction's representative and, more importantly, as the one person willing to tell Klaus Mikaelson exactly what is wrong with him to his face. She is compelled, used, and lied to repeatedly and keeps coming back on her own terms.

Aurora turns her — compelling her to cut her own throat with Aurora's blood in her system — and Lucien's venom finishes her in 2016. Klaus's grief over her is the first time the character is allowed to be simply sad.